Proteins and other biomolecules may be used for a number of diagnostic, monitoring and treatment applications by virtue of having high biological activity and specificity. However, the delivery of biomolecules such as therapeutic proteins, oligonucleotides or other pharmaceutical agents in their unmodified forms may have several limitations which include poor stability, low solubility, short circulating half-lives and immunogenic potential. Frequent administration of the agent may be required, which may increase cost, inconvenience and the risk of adverse reactions.